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Are You Getting the Most Out of Your Renewable Energy?

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Majordennisbloodnok
(@majordennisbloodnok)
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4699 kWhs
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This article is aimed at you if you have recently taken the leap into the world of home renewable energy kits and are keen to get the most from your (probably sizeable) investment. You may have had one or more of quite an array of interesting pieces of technology – an air or ground source heat pump, some solar panels for generating electricity, a battery for storing electricity, an electric car charger; there is quite a list. However, whatever you have had installed, there’s a fair chance it is still basically operating as the installers left it.

This is not necessarily a bad thing, of course. Assuming the installers were reasonably professional, each of your bits of kit is likely to be connected to the Internet so it can be controlled remotely. The chances are high that the manufacturer of your kit will have provided you with an app to install on your phone and probably also a website you can access from a computer, both of which will allow you to change quite a few settings and afford you some control of how your device does its job.

By way of an example, I have an air source heat pump made by Mitsubishi and their offering for controlling it is a product called “Melcloud”. This means they have a Melcloud app for the phone and a Melcloud website, both accessible on the Internet. My air source heat pump uses my Internet connection to talk with Mitsubishi’s systems and uploads information about the current state of affairs.

As you can see from the screenshot, at the moment, the water in the hot water tank is 50.5C and the heat pump is idle in that respect – it isn’t trying to heat the hot water any further.

You can also see that the hot water heating is set to “auto” but that I could tell it to “heat now”. If I selected that, my heat pump would, on one of its very regular double-checks of Mitsubishi’s site, see that the setting has changed and react accordingly i.e. stop anything else it may be doing and concentrate on heating the hot water up to the preset maximum temperature I’ve got set elsewhere deep in the settings. I could, of course, do exactly the same thing using the little control box the installers mounted on the wall just outside the cupboard where the hot water tank lives i.e. the old-school way familiar to any of us whose previous gas or oil boiler wasn’t internet-connected.

This is a perfectly reasonable and maintainable setup, of course, with the added benefit that if I want to change any settings when I’m not at home, then I can. More than once we have gone on holiday and I’ve remembered after we’ve left that I didn’t put the heat pump into holiday mode. Rather than let it heat an empty house for a week or two, I can just change the relevant settings through the Melcloud app exactly as if I were sitting at home. Isn’t technology wonderful?

Similarly, I happen to have a solar PV setup that includes a Growatt inverter and battery. Growatt’s offering in this area is called ShinePhone – an app for your smartphone – but they also let you log in on the web to their web portal for the same functionality.

As you can see from the screenshot, it makes it quite easy to see how much energy is being used, generated, imported, or exported and where it is flowing from and to. It also gives some basic stats along with, not shown but existing further down the screen, graphs and pretty stuff to show what’s been going on since I last checked. There are also settings I could change and, like the heat pump, the inverter would spot the change and change what it’s doing accordingly.

As for my energy supplier – Octopus Energy – I can, of course, see all sorts of graphs and tables showing how much I’ve imported and exported over a given time period and can revel in just how well my setup is working.

At first glance, this all looks pretty smart, so what’s the problem with leaving it all just as it is?

Why Automate?

The cracks in the whole edifice start to show on closer inspection, and they fall into three main categories:

  • Things I’m sure should be possible to change but I can’t see how to (or simply am blocked from doing so).
  • It’s my kit and my data, so why do I have to involve the manufacturer?
  • How can I get the separate parts of the puzzle collaborating?

For instance, I can tell my heat pump to stop heating if I use the box on the wall, but I can’t do it via the app. And try as I might, I can’t set the system time on my inverter through the app without it giving me an error. These are examples of the first point.

Mitsubishi’s Melcloud system was unavailable for a few days earlier this year, so I was unable to get any statistics from them, let alone manage the heat pump. Why should their problem have to be mine if the kit is in my home? There is a good example of the second point.

Finally, illustrating the third point, the agile Octopus import tariff sometimes has prices go negative – they actually pay me to take electricity from them. How can I say “yes please, just fill my battery up” in those situations if the Growatt inverter doesn’t know anything about the Octopus prices?

The inevitable answer is that some form of overseeing system that can read and talk to all your disparate kit is needed.

At this point, however, it is hugely valuable to reflect on what outcomes are important to you.

What Are We Trying to Achieve?

If you want your tech to react in a set and standard way to pre-configurable criteria (come on at a standard time, go off at a standard time, obey a thermostat and so forth), a home automation system isn’t needed for your home to be set up as you want it. Similarly, if you have no need or wish to see any statistics – or the manufacturer’s offerings provide everything you want – then once again, a home automation system is not going to add value here.

Otherwise, there is room for improvement.

  • You may want your heat pump to take into account both the weather and what your solar PV is doing.
  • You may want to get performance data straight from your kit independently from the manufacturer’s app going wrong.
  • You may want to have your heating and energy storage behaving differently depending on whether people are at home or not.

These are just three realistic and understandable ways you might want your stuff to work in a more “joined-up” way. You may well only want one or two of these things. You might want something completely different. You might want all of them. Only you can decide, but now is the time to think about it. No one buys a screwdriver and then looks for ways to use it; we first encounter a job that needs to be done and then get the right tool for the job, so we should be thinking exactly the same way about maximising what you get out of your renewable energy investment and that means understanding what’s important to you.

For me, I was actually fine with stats the manufacturers’ systems were providing me, and I didn’t really care if the Chinese Government was able to see how much leccy I was generating and when; after all, I’d already ensured my systems weren’t sharing any actual personal data. My decision to buy a heat pump was largely based on social responsibility, and I could even afford the running costs to be a slight increase. However, I most certainly didn’t have bottomless pockets so financial efficiency was still important. As a result, my priorities were as follows:

  1. Replace an old fossil fuel boiler that was coming to the end of its useful life.
  2. Ensure the replacement could keep me and my family at least as comfortable as the boiler had.
  3. Significantly reduce the impact on the planet of my necessary heating and hot water.
  4. Do all the above at no more than a slight increase in annual cost, and preferably save money.

There. I had defined what I was trying to achieve. We will revisit this scope later when we start exploring decisions about how to put things into practice.

What Can We Do with What the Installers Left Us?

So, as we have already seen, there is quite a bit we can do with each of our bits of kit using the manufacturer-provided apps and stuff. For instance, Octopus will happily send out notifications of “plunge alerts” i.e. times when their agile unit prices are going to go negative. I have the Octopus app and the ShinePhone (Growatt) apps on my phone, so I could set things up for Octopus to send me a notification whereupon I open the ShinePhone app and tell my battery to start charging from the grid.

Hey presto, I have a home automation system: me.

It doesn’t take much effort, so you may decide you’re fine with working like that and there’s nothing wrong with that decision if it works for you. The KISS principle applies; Keep It Simple, Stupid. Why overcomplicate when you don’t have to?

Similarly, my heat pump and inverter both have schedules coming out of their metaphorical ears. Using only what the installers left us, I can set up schedules to, for instance, avoid the heat pump running during the expensive 4-7pm stretch, and since that time period is reliable, a fit-and-forget schedule like that can work very well. Moreover, since our installers knew what they were doing, they left us with a heat pump that was set up from day one to use a weather compensation curve so it is already configured to run very efficiently.

Is This Enough?

This setup was satisfactory for me for around a year. The heat pump got on with what it was configured to do and demonstrated a slight saving in running costs over the boiler. The solar panels generated leccy, ran electrical items at home, and piled whatever was left into the battery until the latter was full, and then exported the rest. When we needed more electricity than the panels could produce, the system would supply it from the battery if possible, and importing from the grid was the last resort. Put it all together, and we ended up with a considerable yearly saving in monetary terms and a huge saving in environmental terms. Once it was bedded in, however, it became apparent there was still scope for quite a bit of improvement by effectively getting a computer to automatically make the decisions I was making manually.

Hopefully, in this section, I’ve shown you why home automation may be important, the situations that might make it so, and why it is also a good idea not to do stuff just because you can.

If, having read thus far, you are now convinced home automation is unnecessary for you, I’ve achieved something and saved you a load of unnecessary effort. If, on the other hand, you are now interested in pursuing the idea of home automation, please stay with me for the follow-up articles. Building on what I’ve discussed already, I am going to explore three main areas in upcoming articles:

  1. Choosing a system and getting it up and running.
  2. Getting your home automation system communicating with your devices and exploring what you can do as a result.
  3. Extending and enhancing the home automation’s capabilities and starting to make automated choices.

105 m2 bungalow in South East England
Mitsubishi Ecodan 8.5 kW air source heat pump
18 x 360W solar panels
1 x 6 kW GroWatt battery and inverter
Raised beds for home-grown veg and chickens for eggs

"Semper in excretia; suus solum profundum variat"


   
HCas, IanMK13, Morgan and 1 people reacted
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Majordennisbloodnok
(@majordennisbloodnok)
Noble Member Contributor
4699 kWhs
Joined: 3 years ago
Posts: 399
Topic starter  

As I mentioned, there are going to be some follow-up articles. If anyone happens to be in the situation of not yet having a home automation system but wanting to set one up and is interested in actually going through that journey, I'd appreciate it very much if you could PM me.

105 m2 bungalow in South East England
Mitsubishi Ecodan 8.5 kW air source heat pump
18 x 360W solar panels
1 x 6 kW GroWatt battery and inverter
Raised beds for home-grown veg and chickens for eggs

"Semper in excretia; suus solum profundum variat"


   
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Mars
 Mars
(@editor)
Illustrious Member Admin
18462 kWhs
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Joined: 3 years ago
Posts: 2439
 

@majordennisbloodnok I'll circulate this post this week. For the homeowners you're looking for, does the platform (HomeKit, SmartThings, Google Home, Alexa, etc.) matter?

Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb

Follow our sustainability journey at My Home Farm: https://myhomefarm.co.uk


   
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Majordennisbloodnok
(@majordennisbloodnok)
Noble Member Contributor
4699 kWhs
Joined: 3 years ago
Posts: 399
Topic starter  

Thanks, @editor.

Ideally it’d be someone who would like to put some kind of home automation in place but hasn’t made a choice yet about which platform. We’ll be covering what to look for and why in the article so ideally we could walk through that person actually making the decision as I write about it (or rather I write about it in the light of the decisions they make).

105 m2 bungalow in South East England
Mitsubishi Ecodan 8.5 kW air source heat pump
18 x 360W solar panels
1 x 6 kW GroWatt battery and inverter
Raised beds for home-grown veg and chickens for eggs

"Semper in excretia; suus solum profundum variat"


   
Mars reacted
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(@allyfish)
Noble Member Contributor
3341 kWhs
Joined: 2 years ago
Posts: 396
 

Posted by: @majordennisbloodnok

Hey presto, I have a home automation system: me.

Yes, I have the 'Home-me' (TM) integration system too. Similar set-up, stuff like Growatt Solar + batteries + Grant [Chofu] ASHP. All should just be seamlessly working over some integrated communication and control platform but which requires me to co-ordinate it. I've stopped crunching numbers, but I could harvest data to prompt when to make tediously regular adjustments and tweaks.

Having signed up to Agile, my manual control is now this:

Central heating: on at 4am off at 9pm daily during the heating season *

Late spring, summer & early autumn: Nowt. No scheduled battery charging, ASHP heating off. Solar PV provides for our energy requirements and we're usually exporting a modest amount on Octopus fixed outgoing 15p/kWh

Late Autumn - Early Winter  Late Winter - Late Spring: Batteries charged once a day early morning via Growatt's oh-so-clunky 'Shinephone' App setting 3:30am - 6:55am. There's enough daylight still to prop the battery up most days via 3.6kW PV and the ASHP is chugging away on very low power draw.

Winter: batteries charged twice a day 3:30am - 06:55am and 12:30pm - 15:55pm during morning and afternoon low rate periods. ASHP could be working quite hard all day, and dropping into defrost from time to time.

Hot water: ASHP hot water generation scheduled daily from 1pm - 2:15pm or until cylinder thermostat demand satisfied at 55degC. This time slot chosen when the outdoor air enthalpy is highest and least disruption to indoor room temperature.

Knowing when to turn on the scheduled battery charging once a day then twice a day is a best guess based on intuition and seeing how the batteries are holding out on a typical day. Nothing scientific or automated. I don't analyse Agile 1/2 hourly pricing, actual lowest rate periods do vary and I might not sync in exactly with them, but it's there or thereabouts and good n'uff for me. I don't turn everything on in the house if we get negative plunge pricing. Such periods usually coincide with my scheduled charging periods so I can benefit from them.

*the heating season is a weather dependent movable feast. A broad definition is any time the house average room temperature is below about 19degC

 

This post was modified 2 months ago 3 times by AllyFish

   
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Toodles
(@toodles)
Famed Member Contributor
6432 kWhs
Joined: 2 years ago
Posts: 1009
 

@allyfish Not being one for writing lines of code, I too would be interested in some form of ‘Master Controller’ that would interface with my OE Agile supply, my Powerwalls, my Sunamp DHW system, Myenergi Eddi and the PV output - plus of course, keeping the cost of supplying all those Watts to the Homely controlled ASHP. I think I would get a warm feeling from a system that could be relied upon to look after my interests if I was ill or absent - my wife is not at all technical and a system that would work without input from her beyond perhaps turning on heating and off at the end of chilly days in the spring would be the most friendly. Don’t want much do I!? Regards, Toodles.

This post was modified 2 months ago by Mars

Toodles, 76 years young and hoping to see 100 and make some ROI on my renewable energy investment!


   
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